1. Field of the Invention
The present invention relates to wrenches, and more particularly to a hand wrench adapted to cooperate with a second wrench. When leverage beyond that available due to the length of one wrench is required, the wrench engages a second wrench. The second wrench extends the effective length of the first, so that additional torque may be applied.
2. Description of the Prior Art
Wrenches may occasionally be of insufficient length to offer leverage required to perform a given task. In such cases, the person using the wrench is obliged to extend the effective length of the wrench in order to develop sufficient torque to complete the task at hand. The user may resort to methods such as slipping a pipe over the wrench. Alternatively, the prior art has suggested apparatus for solving this problem.
An extension for the handle of a wrench is shown in U.S. Pat. No. 4,960,014, issued to Roy C. Kelley on Oct. 2, 1990. Kelley's extension comprises a planar member having two hook-like projections for engaging the wrench. By contrast, the present invention provides a notch in the head of a wrench so that this wrench cooperatively engages the jaws of a second, open ended wrench.
U.S. Pat. No. 4,811,638, issued to Ernst Kertzscher on Mar. 14, 1989, describes a wrench having an opening formed therein for receiving the square drive of a ratchet wrench. The notch formed in the present invention differs from the square hole of Kertzscher in location on the head of the wrench, in that it does not penetrate entirely through the wrench, and that it enables a web of structural material to extend continuously along the opening of the jaw of the wrench for resisting torsional forces generated by turning the wrench against resistance.
Wrenches displaying variations to the usual configuration of the jaws of an open end wrench are seen in U.S. Pat. No. 3,850,057, issued to James Preston Evans on Nov. 26, 1974, and U.S. Pat. No. 5,136,902, issued to Homer W. Ma on Aug. 11, 1992. Modification of the openings of the wrench in this latter group affect the interior configuration of the jaw opening when seen in profile, and would not enable engagement by a second, conventional open end wrench in the manner of the present invention. By contrast, the notch formed in the wrench head of the present invention is oriented not to affect the profile of the opening for receiving a bolt head, and adapts a box end wrench to engage an open ended wrench. The improvements of Evans and Ma are disposed upon heads of open end wrenches, whereas the present invention improves upon heads of box end wrenches.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.